After practising in Photoshop I learned that Actions are real time savers.
Yes ,there are many short cuts like CTRL + C, CTRL + V for copy and paste ( like many windows based applications as we all already know ) . But a better idea for saving time is to assign some functions to some keys. You can do it with Actions in Photoshop.
For instance I assigned F2 to equalize and F3 to undo and F1 to inverting the selection area. It is easier for me now to work with a single stroke ! I check spots and stains with F2 ( equalizing ) and undo it with F3 if I see any and clean it with brush and check it with a single keystroke again. Do not need to use menus or other two - three key combined shortcuts.
If you are new to Photoshop than open it and click to F9. You will see actions. Click to "new action" at the bottom and record whatsoever you want to use later.
Thanks for reading